{"id":99,"date":"2024-01-25T10:30:50","date_gmt":"2024-01-25T10:30:50","guid":{"rendered":"https:\/\/learnpython.elegantwallp.com\/?p=99"},"modified":"2024-01-25T10:30:50","modified_gmt":"2024-01-25T10:30:50","slug":"python-set-difference","status":"publish","type":"post","link":"https:\/\/learnpython.elegantwallp.com\/2024\/01\/25\/python-set-difference\/","title":{"rendered":"Python Set Difference"},"content":{"rendered":"\n

Summary<\/strong>: in this tutorial, you\u2019ll learn about the Python Set difference and how to use it to find the difference between two or more sets.<\/p>\n\n\n\n

Introduction to the Python Set difference<\/h2>\n\n\n\n

The difference between the two\u00a0sets\u00a0results in a new set that has elements from the first set which aren\u2019t present in the second set.<\/p>\n\n\n\n

Suppose you have the following\u00a0s1<\/code>\u00a0and\u00a0s2<\/code>\u00a0sets:<\/p>\n\n\n\n

s1 = {'Python', 'Java', 'C++'} s2 = {'C#', 'Java', 'C++'}<\/code>Code language: JavaScript (javascript)<\/small><\/code><\/pre>\n\n\n\n
The difference between\u00a0s1<\/code>\u00a0and\u00a0s2<\/code>\u00a0sets results in the following set with one element:<\/p>\n\n\n\n
{'Python'} <\/code>Code language: JavaScript (javascript)<\/small><\/code><\/pre>\n\n\n\n
\u2026because there is only 'Python'<\/code> element from the first set that doesn\u2019t exist in the second set.<\/p>\n\n\n\n
The set difference isn\u2019t commutative. The difference between the\u00a0s2<\/code>\u00a0and\u00a0s1<\/code>\u00a0sets returns the following set:<\/p>\n\n\n\n
{'C#'}<\/code>Code language: JavaScript (javascript)<\/small><\/code><\/pre>\n\n\n\n
The following Venn diagram illustrates the difference between the s1<\/code> and s2<\/code> sets:<\/p>\n\n\n\n
\"Python<\/figure>\n\n\n\n
And the following Venn diagram illustrates the difference between s2<\/code> and s1<\/code> sets:<\/p>\n\n\n\n
\"Python<\/figure>\n\n\n\n
In Python, you can use the set difference()<\/code> method or set difference operator (-<\/code>) to find the difference between sets.<\/p>\n\n\n\n
1) Using Python Set difference() method to find the difference between sets<\/h3>\n\n\n\n
The\u00a0Set<\/code>\u00a0type has a\u00a0difference()<\/code>\u00a0method that returns the difference between two or more sets:<\/p>\n\n\n\n
set1.difference(s2, s3, ...)<\/code>Code language: CSS (css)<\/small><\/code><\/pre>\n\n\n\n
For example, you can use the set\u00a0difference()<\/code>\u00a0method to find the difference between\u00a0s1<\/code>\u00a0and\u00a0s2<\/code>\u00a0sets:<\/p>\n\n\n\n
s1 = {'Python', 'Java', 'C++'} s2 = {'C#', 'Java', 'C++'} s = s1.difference(s2) print(s)<\/code>Code language: PHP (php)<\/small><\/code><\/pre>\n\n\n\n
Output:<\/p>\n\n\n\n
{'Python'}<\/code>Code language: JavaScript (javascript)<\/small><\/code><\/pre>\n\n\n\n
And this example shows how to use the set\u00a0difference()<\/code>\u00a0method to find the difference between\u00a0s2<\/code>\u00a0and\u00a0s1<\/code>\u00a0sets.<\/p>\n\n\n\n
s1 = {'Python', 'Java', 'C++'} s2 = {'C#', 'Java', 'C++'} s = s2.difference(s1) print(s)<\/code>Code language: PHP (php)<\/small><\/code><\/pre>\n\n\n\n
Output:<\/p>\n\n\n\n
{'C#'}<\/code>Code language: JavaScript (javascript)<\/small><\/code><\/pre>\n\n\n\n
Note that the difference()<\/code> method returns a new set. It doesn\u2019t change the original sets.<\/p>\n\n\n\n
2) Using Python set difference operator (-) to find the difference between sets<\/h3>\n\n\n\n
Besides the difference()<\/code> method, Python provides you with the set difference operator (-<\/code>) that allows you to find the difference between sets.s = s1 - s2<\/code><\/p>\n\n\n\n
The following example uses the difference operator (-<\/code>) to find the difference between the\u00a0s1<\/code>\u00a0and\u00a0s2<\/code>\u00a0sets:<\/p>\n\n\n\n
s1 = {'Python', 'Java', 'C++'} s2 = {'C#', 'Java', 'C++'} s = s1 - s2 print(s)<\/code>Code language: PHP (php)<\/small><\/code><\/pre>\n\n\n\n
And this example use the set difference operator to return the difference between\u00a0s2<\/code>\u00a0and\u00a0s1<\/code>:<\/p>\n\n\n\n
s1 = {'Python', 'Java', 'C++'} s2 = {'C#', 'Java', 'C++'} s = s2 - s1 print(s) <\/code>Code language: PHP (php)<\/small><\/code><\/pre>\n\n\n\n
Output:<\/p>\n\n\n\n
{'C#'}<\/code>Code language: JavaScript (javascript)<\/small><\/code><\/pre>\n\n\n\n
The set difference() method vs set difference operator (-)<\/h3>\n\n\n\n
The set\u00a0difference()<\/code>\u00a0method can accept one or more\u00a0iterables\u00a0(e.g.,\u00a0strings,\u00a0lists,\u00a0dictionaries) while the set difference operator (-<\/code>) only allows sets.<\/p>\n\n\n\n
When you pass iterables to the set difference()<\/code> method, it\u2019ll convert the iterables to sets before performing the difference operation.<\/p>\n\n\n\n
The following shows how to use the set\u00a0difference()<\/code>\u00a0method with a list:<\/p>\n\n\n\n
scores = {7, 8, 9} numbers = [9, 10] new_scores = scores.difference(numbers) print(new_scores) <\/code>Code language: PHP (php)<\/small><\/code><\/pre>\n\n\n\n
However, if you use the set difference operator (-<\/code>) with iterables, you\u2019ll get an error:<\/p>\n\n\n\n
scores = {7, 8, 9} numbers = [9, 10] new_scores = scores - numbers print(new_scores) <\/code>Code language: PHP (php)<\/small><\/code><\/pre>\n\n\n\n
Error:<\/p>\n\n\n\n
TypeError: unsupported operand type(s) for -: 'set' and 'list'<\/code><\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"
Summary: in this tutorial, you\u2019ll learn about the Python Set difference and how to use it to find the difference between two or more sets. Introduction to the Python Set difference The difference between the two\u00a0sets\u00a0results in a new set that has elements from the first set which aren\u2019t present in the second set. Suppose […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[21],"tags":[],"class_list":["post-99","post","type-post","status-publish","format-standard","hentry","category-7-sets"],"_links":{"self":[{"href":"https:\/\/learnpython.elegantwallp.com\/wp-json\/wp\/v2\/posts\/99","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/learnpython.elegantwallp.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/learnpython.elegantwallp.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/learnpython.elegantwallp.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/learnpython.elegantwallp.com\/wp-json\/wp\/v2\/comments?post=99"}],"version-history":[{"count":1,"href":"https:\/\/learnpython.elegantwallp.com\/wp-json\/wp\/v2\/posts\/99\/revisions"}],"predecessor-version":[{"id":100,"href":"https:\/\/learnpython.elegantwallp.com\/wp-json\/wp\/v2\/posts\/99\/revisions\/100"}],"wp:attachment":[{"href":"https:\/\/learnpython.elegantwallp.com\/wp-json\/wp\/v2\/media?parent=99"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/learnpython.elegantwallp.com\/wp-json\/wp\/v2\/categories?post=99"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/learnpython.elegantwallp.com\/wp-json\/wp\/v2\/tags?post=99"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}